CN112112807B - Multistage differential water pump of noise reduction - Google Patents

Abstract

The invention discloses a multistage differential water pump capable of reducing noise, which comprises a shell, a driving stator assembly and a rotor assembly, wherein the driving stator assembly and the rotor assembly are arranged on the shell, the driving stator assembly comprises at least two driving stators which are axially distributed along the shell, the rotor assembly comprises multistage impeller modules, each stage of impeller module in the multistage impeller modules comprises a rotor and an impeller assembly arranged on the rotor, each driving stator provides a rotating driving force for the rotor of the corresponding one stage of impeller module, and the rotating speed of the corresponding rotor is controlled by setting different voltages for different driving stators, so that the differential rotation of the multistage impeller modules is realized. The invention not only realizes multistage supercharging transmission, reduces fluid resistance and improves the lift of the pump, but also obviously reduces noise caused by fluid pressure transformation due to the change of the rotating speed among multistage impellers.

Description

A multi-stage differential water pump with reduced noise

Technical Field

The present invention belongs to the technical field of water pumps, in particular to a magnetically suspended multi-stage differential shaftless water pump, which can be widely used for water transportation, and can be used in water conservancy industry, hydropower industry, sewage treatment industry, etc.

Background Art

A water pump is a machine that transports liquids or increases the pressure of liquids. It transfers the mechanical energy of the prime mover or other external energy to the liquid to increase the energy of the liquid. It is mainly used to transport liquids including water, oil, acid and alkali liquids, emulsions, suspensions and liquid metals. It is the most common industrial equipment in modern industrial production and plays an important role in almost all fields of modern industry.

Water pumps are divided into positive displacement pumps and vane pumps. Vane pumps include centrifugal pumps, axial flow pumps, mixed flow pumps, etc., all of which have impellers and pump shafts in structure. The pump shaft is driven by the output shaft of the motor, and then the impeller rotates to achieve the function of the water pump. The high-speed operation of the impeller and the pump shaft brings various disadvantages of traditional water pumps: such as low conversion efficiency, excessive power consumption, limited head, easy bearing wear, frequent maintenance, huge noise, etc. The development of a shaftless water pump is expected to solve these disadvantages and achieve the effects of high efficiency, energy saving, durability and environmental protection. Patent CN205225763U discloses a shaftless pump, which is combined with a rotating pipeline through a fixed pipeline, and two sets of load-bearing bearings are used to rotate with the rotating pipeline. The positioning bearings are arranged in the corresponding grooves that cooperate with each other to limit the displacement of the pipeline and make the water pump run more stably. Patent CN1138919C discloses a shaftless sealed rotor series pipeline pump. It includes a hollow housing, an annular rotor rotatably mounted in the housing, and an annular stator fixedly mounted in the housing and surrounding the rotor. Patent CN102619788A discloses an integrated shaftless motor axial flow pump. The pump is provided with a pump casing with connecting flanges at both ends, a pump impeller is centrally arranged in the internal cavity of the pump casing, a guide vane is arranged in the internal cavity of the pump casing located on the downstream side of the axial flow pump, a rotor fixing ring is arranged on the outer edge of the pump impeller, the drive motor rotor is assembled on the rotor fixing ring, the rotor fixing ring is fixed to the inner side of the pump casing through a fixing ring bearing, and a groove is arranged at a position corresponding to the drive motor rotor on the inner side of the pump casing, and the drive motor stator is assembled in the groove. Patent CN102055277A discloses a shaftless motor used in conjunction with a mud pump. The rotor of the motor is provided with an installation cavity inside, and rotor auxiliary iron is arranged on the outside in sequence; permanent magnet blocks are distributed on the outer circumferential surface of the rotor auxiliary iron at uniform intervals of N and S levels, a winding stator is arranged on the outside of the permanent magnet blocks, and a casing is installed on the outside of the stator, and the two ends of the casing are respectively fixedly connected to the inner end cover and the outer end cover, and the inner end cover is fixed to the equipment by the equipment stop.

Summary of the invention

The technical problem to be solved by the present invention is to provide a multi-stage differential water pump with reduced noise, realize multi-stage boost transmission and reduce fluid resistance, and can further reduce noise.

In order to solve the above technical problems, the present invention adopts the following technical solutions: a multi-stage differential water pump with reduced noise, comprising a housing, a driving stator assembly installed on the housing, and a rotor assembly, wherein the driving stator assembly comprises at least two driving stators distributed along the axial direction of the housing, and the rotor assembly comprises a multi-stage impeller module, wherein each stage of the multi-stage impeller module comprises a rotor and an impeller assembly installed on the rotor, and each driving stator provides a rotational driving force for the rotor of the corresponding first-stage impeller module, and the rotation speed of the corresponding rotor is controlled by setting different voltages for different driving stators, thereby realizing differential rotation of the multi-stage impeller module.

Preferably, the rotor comprises a cylindrical steel ring and a plurality of permanent magnets evenly distributed along the circumference of the cylindrical steel ring.

Preferably, the impeller assembly comprises an impeller and a front cover plate and a variable diameter guide body respectively arranged on the front and rear sides of the impeller, and the variable diameter guide body is connected to the cylindrical steel ring.

Preferably, the cylindrical steel ring is connected to the variable diameter guide body through a bolt structure, the inner side of the cylindrical steel ring is provided with a variable diameter guide body installation groove, the variable diameter guide body includes a variable diameter guide body rear cover, the outer side of the variable diameter guide body rear cover is provided with a bolt structure installation groove, and the bolt structure is embedded in the bolt structure installation groove and the variable diameter guide body installation groove.

Preferably, the rotor assembly also includes a self-priming impeller module located on the front side of the multi-stage impeller module, the self-priming impeller module includes the rotor and impeller assembly, a self-priming port is provided at the center of the front cover plate of the self-priming impeller module, the impeller of the self-priming impeller module is connected to a self-priming impeller shaft, the self-priming impeller shaft extends forward from the self-priming port and is connected to self-priming blades, and the driving stator assembly also includes a driving stator arranged corresponding to the rotor of the self-priming impeller module.

Preferably, the self-priming impeller module and the multi-stage impeller module, and two adjacent stages of the multi-stage impeller module are rotatably connected via an impeller module connector.

Preferably, the impeller module connector includes a front flange body, a rear flange body and a ball bearing, the ball bearing includes a bearing outer ring, balls and a bearing inner ring, the front flange body is fixed to the cylindrical steel ring of the front rotor and to the bearing outer ring, and the rear flange body is fixed to the cylindrical steel ring of the rear rotor and to the bearing inner ring.

Preferably, the side wall of the front flange body is provided with a front bearing fixing hole, and the side wall of the rear flange body is provided with a rear bearing fixing hole. The front flange body is fixed to the bearing outer ring bolts through the front bearing fixing hole, and the rear flange body is fixed to the bearing inner ring bolts through the rear bearing fixing hole.

Preferably, the front and rear end surfaces of the cylindrical steel ring are correspondingly provided with flange mounting grooves that are embedded with the front flange body and the rear flange body, the front wall of the front flange body is provided with a front flange hole, and the rear wall of the rear flange body is provided with a rear flange hole. The front flange body is fixed to the flange mounting groove bolts on the front rotor through the front flange hole, and the rear flange body is fixed to the flange mounting groove bolts on the rear rotor through the rear flange hole.

Preferably, the front and rear end surfaces of the cylindrical steel ring are provided with annular grooves which engage with the ball bearings.

The technical solution adopted by the present invention has the following beneficial effects:

The driving stator provides the driving force for the rotor to rotate under the action of electric current. By setting different voltages for different driving stators to control the speed of the corresponding rotor, differential rotation of the multi-stage impeller module is achieved. This not only realizes multi-stage pressurized transmission and reduces fluid resistance, thereby increasing the pump head; the speed change between the multi-stage impellers also significantly reduces the noise caused by fluid pressure change.

The specific technical solutions and beneficial effects of the present invention will be described in detail in the following specific embodiments in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

FIG1 is an overall structural diagram of a magnetically suspended multi-stage differential shaftless water pump provided by the present invention, wherein the arrows indicate the flow of the fluid passing through the pump when the pump is running;

FIG2 is an overall structural expansion diagram of a magnetically suspended multi-stage differential shaftless water pump provided by the present invention;

Fig. 3 is a cross-sectional view of the housing;

Fig. 4 is a shell expansion diagram;

Fig. 5 is a cross-sectional view of the rear housing;

Fig. 6 is an expanded view of the rear shell;

Figure 7-1 is a schematic diagram of the cylinder expansion;

Figure 7-2 is the second schematic diagram of the cylinder expansion;

Figure 7-3 is an axial view of the cylinder;

Figure 7-4 is an axonometric view of the cylinder;

Figure 8-1 is a front view of the rotor assembly;

Fig. 8-2 is a cross-sectional view taken along line A-A in Fig. 8-1;

Figure 9-1 is a first schematic diagram of the expansion of the rear end impeller body;

Figure 9-2 is a radial schematic diagram of the rear end impeller assembly;

Figure 9-3 is an axonometric view of the rear impeller assembly;

FIG10 is a schematic diagram of the expansion of a self-priming impeller module and a multi-stage impeller module;

FIG11 is a schematic diagram of the expansion of the rotor;

Figure 12-1 is an axonometric view of a variable diameter guide body;

FIG12-2 is a radial schematic diagram of a variable diameter guide body;

FIG12-3 is an axial schematic diagram of a variable diameter guide body;

FIG13-1 is an expanded schematic diagram of a self-priming impeller module;

Figure 13-2 is the second expanded schematic diagram of the self-priming impeller module;

FIG14 is a schematic diagram of the structure of a multi-stage impeller module;

Figure 15-1 is a schematic diagram of the impeller module connector structure;

Figure 15-2 is a schematic diagram of the expansion of the impeller module connector;

In the figure:

Rear impeller 1, impeller tray 2, rear cover 3, middle plate 4, cylinder 5, front shell 6, grille 7, grille flange 8, front magnetic suspension stator 9, front permanent magnet 10, rotor flange 11, fixed flange 12, guide cover 13, rear permanent magnet 14, rear magnetic suspension stator 15, rear impeller cover 16;

Cylindrical steel ring 20, variable diameter guide body rear cover 21, impeller b22, front cover plate b23, bolt body structure a26, bolt body structure b27, permanent magnet steel 28, bolt body 29;

Front cover a30, self-priming blades 31, impeller a39;

Electric control box 40, bolt body 41, driving stator 42, bolt joint groove 43, bolt body groove 1 44, bolt body groove 2 45, variable diameter guide body mounting groove 46, bolt groove 47, permanent magnet steel mounting groove 48, bolt body structure mounting groove 49;

Flange mounting groove 50, front flange body 51, bearing outer ring 52, ball 53, bearing inner ring 54, rear flange body 55, front flange hole 56, bearing front fixing hole 57, bearing rear fixing hole 58, rear flange hole 59,

Self-priming impeller module a, multi-stage impeller module b, rear end impeller body c.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. For example, the following words indicating orientation or positional relationship, such as "front", "rear", "inner", "outer", "axial", "radial", etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device/element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Those skilled in the art will appreciate that, in the absence of conflict, the features in the following embodiments and implementations may be combined with each other.

As shown in Figures 1 and 2, the magnetic suspension multi-stage differential shaftless water pump of the present invention includes a housing, a driving stator assembly and a magnetic suspension stator and rotor assembly installed on the housing, a front-to-back circulating water flow channel is provided between the rotor assembly and the driving stator assembly, the driving stator assembly includes at least two driving stators 42 distributed along the axial direction of the housing, and the rotor assembly includes a magnetic suspension permanent magnet and a multi-stage impeller module b. The rotor assembly is in a magnetic suspension state by cooperating with the magnetic suspension stator and the magnetic suspension permanent magnet. Each stage of the impeller module in the multi-stage impeller module b includes a rotor and an impeller assembly installed on the rotor, and each driving stator provides a driving force for the rotor of the corresponding first-stage impeller module to rotate. Different voltages are set for different driving stators to control the speed of the corresponding rotor, so as to realize differential rotation of the multi-stage impeller module.

Since the rotor assembly is in a magnetic suspension state through the cooperation of the magnetic suspension stator and the magnetic suspension permanent magnet, a shaftless design is realized, making the pump small in size, high in efficiency and long in service life.

Through the differential rotation of the multi-stage impeller module, not only multi-stage pressurization transmission is achieved and fluid resistance is reduced, thereby increasing the pump head; but the speed change between the multi-stage impellers also significantly reduces the noise caused by fluid pressure change.

The housing of the magnetic suspension multi-stage differential shaftless water pump shown in Figures 3 and 4 includes a front housing 6, a cylinder 5, a middle plate 4 and a rear housing. The front housing 6 is connected to the cylinder 5 by bolts. The middle plate 4 is connected to the cylinder 5 by bolts. An electric control box 40 is installed outside the cylinder 5, and the cylinder 5 is provided with a wiring hole, and the wire passes through the wiring hole to connect with the electric control box 40. The middle plate 4 is connected to the rear housing by bolts and nuts.

Among them, the electric control box 40 includes a power output circuit module, a magnetic suspension control module, and a power management module, wherein the power output circuit module controls each drive stator of the drive stator assembly, so that different drive stators are set with different voltages to control the speed of the corresponding rotor. The magnetic suspension control module controls the magnetic suspension stator so that the stator and the rotor assembly are kept in a suspended state by magnetic force. Furthermore, the magnetic suspension control module includes a position adjustment control system, which is electrically connected to the distance sensor and the magnetic suspension stator, and controls the output power of the magnetic suspension stator after receiving the distance value sensed by the distance sensor, thereby controlling the magnetic force between the magnetic suspension stator and the rotor to maintain the suspended state.

Furthermore, the front shell 6 is provided with a water flow channel inlet, a grille step is provided at the front end of the water flow channel inlet, the grille 7 is placed on the grille step and fixed by the grille flange 8. A front magnetic suspension stator step is provided at the rear end of the water flow channel inlet, and the front magnetic suspension stator 9 is installed on the front magnetic suspension stator step.

As shown in Figures 3 to 6, the rear shell includes three parts: a guide cover 13, an impeller tray 2 and a rear cover 3. The guide cover 13, the impeller tray 2 and the rear cover 3 are connected in a chimeric manner. The rear cover 3 is connected to the middle plate 4 by bolts and nuts, and the guide cover 13 and the impeller tray 2 are fixed at the same time. A water flow channel outlet is provided at the center of the rear cover 3.

Furthermore, a support hole is provided at the center of the impeller tray 2, and an annular groove is provided around the support hole. A rear magnetic suspension stator 15 is installed on the impeller tray 2, and the rear magnetic suspension stator 15 is embedded in the annular groove.

As shown in Fig. 7-1 to Fig. 7-4, multiple groups of driving stators 42 are installed in the axial direction inside the cylinder 5, and the driving stators 42 are provided with torque windings. The outer wall of the driving stator 42 is provided with a bolt body groove 1 44 and a bolt body groove 2 45, and the driving stator 42 and the cylinder 5 are engaged through a bolt body 41, and a bolting groove 43 is provided on the inner wall of the cylinder. The bolt body 41 is bolted with the bolt body groove 1 44, the bolt body groove 2 45 and the bolting groove 43 to fix the driving stator 42 and the cylinder 5.

Furthermore, the space between the driving stator 42 and the cylinder 5 is filled with a waterproof and non-conductive filler.

As shown in Fig. 8-1 and Fig. 8-2, the rotor assembly of the magnetically suspended multi-stage shaftless water pump includes a front permanent magnet 10, a rear permanent magnet 14, a self-priming impeller module a, a multi-stage impeller module b, and a rear impeller body c. The front permanent magnet 10 is installed at the front end of the self-priming impeller module a, and the rear permanent magnet 14 is installed at the rear end of the rear impeller body c.

As shown in Figures 9-1 to 9-3, the rear impeller body c includes a rear impeller cover 16, a rear impeller 1, a rotor flange 11, and a fixed flange 12. The fixed flange 12 has multiple screw holes, which are distributed on two concentric circles of different diameters. The rear impeller cover 16 is bolted to the outer screw holes of the fixed flange 12, and the rear impeller cover 16 is connected to the rear impeller 1 by an interlocking bolt. The rotor flange 11 is bolted to the inner screw holes of the fixed flange 12.

Furthermore, the periphery of the rear impeller 1 is provided with radial protrusions along the circumferential direction, and the periphery of the rear impeller cover 16 is provided with embedded grooves along the circumferential direction, and the radial protrusions are embedded in the embedded grooves. The rear end of the rear impeller 1 is provided with an annular groove around the impeller shaft, and the rear permanent magnet 14 is embedded in the annular groove of the rear impeller. The impeller shaft of the rear impeller is supported by the support hole.

As shown in FIG. 10 , the self-priming impeller module a is connected in series with the multi-stage impeller module b.

As shown in FIG11 , the self-priming impeller module a and the multi-stage impeller module b are both provided with rotors. The rotor includes a cylindrical steel ring 20 and a plurality of permanent magnets 28 evenly installed along the circumference of the cylindrical steel ring 20. The outer side of the cylindrical steel ring 20 is provided with a permanent magnet installation groove 48, the inner side is provided with a variable diameter guide body installation groove 46, and the front and rear sides are provided with an annular groove 18 and a flange installation groove 50. The annular groove 18 is located radially outside the flange installation groove 50, and the two form a step shape, wherein the rotor flange 11 is embedded in the flange installation groove 50.

Specifically, the impeller assembly includes an impeller and a front cover plate and a variable diameter guide body respectively covering the front and rear sides of the impeller. The centers of the front cover plate and the variable diameter guide body are provided with water flow channel holes for water flow to pass through. The variable diameter guide body is connected to the cylindrical steel ring 20.

As shown in Fig. 12-1 to Fig. 12-3, the variable diameter guide body is composed of a tether structure a26, a tether structure b27 and a variable diameter guide body rear cover 21. The outer side of the variable diameter guide body rear cover 21 is provided with a tether structure installation groove 49, and the tether structure a26 and the tether structure b27 are connected and installed on the tether structure installation groove 49 of the variable diameter guide body rear cover 21. Among them, the tether structure b27 is inserted into the cylindrical steel ring 20 through the variable diameter guide body installation groove 46 on the inner side of the cylindrical steel ring 20, and the tether structure b27 is rotated to be engaged with the tether groove 47 on the inner side of the cylindrical steel ring 20, and then the tether 29 is inserted into the tether groove 47 on the inner side of the cylindrical steel ring 20. The above design makes it easy to disassemble and install the tether structure variable diameter guide body to repair the impeller blades.

As shown in Figures 13-1 and 13-2, the self-priming impeller module a includes an impeller a39, a front cover a30, and a self-priming blade 31. Among them, the impeller a39 is provided with an impeller shaft, and the self-priming blade 31 is embedded in the impeller shaft of the impeller a39 and fixed by bolts to form an impeller body. The center of the front cover a30 is provided with a self-priming port, and the impeller shaft extends forward from the self-priming port and connects the self-priming blade 31. The impeller body, the front cover a30, and the variable diameter guide body rear cover 21 are fixed by bolts through the variable diameter guide body embedded in the impeller body to form the self-priming impeller module a.

Of course, those skilled in the art can understand that the driving stator assembly also includes a driving stator arranged corresponding to the rotor of the self-priming impeller module. The self-priming impeller module a and the multi-stage impeller module b also rotate at a differential speed.

As shown in Fig. 14, the multi-stage impeller module b comprises an impeller b22 and a front cover plate b23. The impeller b22, the front cover plate b23 and the variable diameter guide body rear cover 21 are fixed by variable diameter guide body embedded bolts to form the multi-stage impeller module b.

In order to realize the rotational connection between the self-priming impeller module a and the multi-stage impeller module b, and the independent rotation between the stages of the multi-stage impeller module b, an impeller module connector is also provided. As shown in Figures 15-1 and 15-2, the impeller module connector includes a front flange body 51, a rear flange body 55 and a ball bearing, wherein the ball bearing is engaged with the annular groove 18. The ball bearing includes a bearing outer ring 52, a ball 53 and a bearing inner ring 54. Among them, the side wall of the front flange body 51 is provided with a bearing front fixing hole 57, the front wall is provided with a front flange hole 56, the side wall of the rear flange body 55 is provided with a bearing rear fixing hole 58, and the rear wall is provided with a rear flange hole 59.

The front flange body 51 is bolted to the flange mounting groove 50 of the cylindrical steel ring 20 of the self-priming impeller module a or the multi-stage impeller module b through the front flange hole 56. The rear flange body 55 is bolted to the flange mounting groove 50 of the cylindrical steel ring 20 of the multi-stage impeller module b through the rear flange hole 59. The front flange body 51 is bolted to the bearing outer ring 52 through the bearing front fixing hole 57, and the rear flange body 55 is bolted to the bearing inner ring 54 through the bearing rear fixing hole 58.

In addition, in order to achieve the connection between the last stage of the multi-stage impeller module b and the rear impeller body c, the rotor flange 11 of the rear impeller body c is supported in the flange mounting groove 50 of the last stage of the multi-stage impeller module b to achieve bolt connection between the two.

In the above technical solution, the self-priming impeller module a and the multi-stage impeller module b are sequentially arranged along the axial direction of the rotor assembly. The self-priming impeller module a and the multi-stage impeller module b, as well as the stages of the multi-stage impeller module b are rotatably connected through an impeller module connector. Therefore, while being axially connected as a whole, they can all rotate independently.

The front magnetic suspension stator 9 cooperates with the front permanent magnet 10, and the rear magnetic suspension stator 15 cooperates with the rear permanent magnet 14. The entire rotor assembly is in a magnetic suspension state through the cooperation of the magnetic suspension stator and the magnetic suspension permanent magnet, realizing a shaftless design. The distance sensor detects the distance between the magnetic suspension stator and the magnetic suspension permanent magnet, and adjusts the output power according to the distance value. Specifically, when the distance between the front magnetic suspension stator and the front magnetic suspension permanent magnet is greater than the threshold, the magnetic poles of the front magnetic suspension stator are adjusted to be different from the magnetic poles of the magnetic suspension permanent magnet, and the rotor is pulled into the threshold range; when the distance between the front magnetic suspension stator and the front magnetic suspension permanent magnet is less than the threshold, the magnetic poles of the front magnetic suspension stator are adjusted to be the same as the magnetic poles of the magnetic suspension permanent magnet, and the rotor is pushed into the threshold range; the larger the deviation range, the greater the power of the magnetic suspension stator.

Since the self-priming impeller module a and the multi-stage impeller module b both adopt a modular impeller design, the impeller can be easily replaced.

In addition, in the above-mentioned rotor assembly, an annular circulating water flow channel is formed between the rotor and the driving stator in the self-priming impeller module a and the multi-stage impeller module b, connecting the guide cover 13 and the water flow channel entrance, realizing water circulation while reducing friction, thereby reducing noise and energy consumption.

Figure 1 shows the fluid flow path of the magnetic suspension multi-stage differential shaftless water pump of the present invention when it is working. The fluid enters the pump cavity through the water flow channel inlet on the front shell 6, and the water at its front end and the circulating water flow channel is sucked into the pump body by the self-priming blades 31.

When water enters the pump body, it first passes through the impeller a39 in the self-priming impeller module a for centrifugal drive. The water obtains the kinetic energy provided by the blades and moves toward the periphery of the impeller. The water is turned to the back of the impeller a39 through the variable-diameter guide body rear cover 21 and flows into the multi-stage impeller module b from the outlet of the variable-diameter guide body rear cover 21. Similarly, the water passes through each stage of the multi-stage impeller module b in turn, and is accelerated multiple times to achieve multi-stage pressurized transmission.

Finally, the water is sent to the guide channel of the guide cover 13 through the rear impeller 11, and the water is divided into two paths in the guide channel of the guide cover 13, one path flows out through the water flow channel outlet of the rear cover 3, and the other path circulates toward the water flow channel inlet in the front through the circulating water flow channel.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims (4)

1. A multistage differential water pump of noise reduction, its characterized in that: comprises a shell, a driving stator assembly and a rotor assembly, wherein the driving stator assembly is arranged on the shell, the driving stator assembly comprises at least two driving stators which are axially distributed along the shell, the rotor assembly comprises a multi-stage impeller module, each stage of impeller module in the multi-stage impeller module comprises a rotor and an impeller assembly arranged on the rotor, each driving stator provides a rotating driving force for the rotor of the corresponding one-stage impeller module, the rotating speeds of the corresponding rotor are controlled by setting different voltages for different driving stators, the multi-stage impeller module is in a magnetic suspension state through the cooperation of a magnetic suspension stator and a magnetic suspension permanent magnet, the rotor comprises a cylinder steel ring and a plurality of permanent magnet steels which are uniformly distributed along the circumference of the cylinder steel ring, the impeller assembly comprises impellers, a front cover plate and a reducing guide body which are respectively covered on the front side and the rear side of the impellers, the reducing guide body is connected with the cylinder steel ring, the rotor assembly further comprises a self-suction impeller module positioned at the front side of the multi-stage impeller module, the self-suction impeller module comprises a rotor and an impeller assembly, a self-suction port is arranged at the center of a front cover plate of the self-suction impeller module, an impeller of the self-suction impeller module is connected with a self-suction impeller shaft, the self-suction impeller shaft extends forwards from the self-suction port and is connected with self-suction blades, the driving stator assembly further comprises a driving stator which is arranged corresponding to the rotor of the self-suction impeller module, the self-suction impeller module is connected with the multi-stage impeller module in a rotating way through an impeller module connecting body between two adjacent stages of the multi-stage impeller module, the impeller module connecting body comprises a front flange body, a rear flange body and a ball bearing, the ball bearing comprises a bearing outer ring, balls and a bearing inner ring, the front flange body is fixed with the cylinder steel ring of the front side rotor and is fixed with the bearing outer ring, the rear flange body is fixed with the cylinder steel ring of the rear side rotor and is fixed with the bearing inner ring, the side wall of the front flange body is provided with a bearing front fixing hole, the side wall of the rear flange body is provided with a bearing rear fixing hole, the front flange body is fixed with the bearing outer ring through the bearing front fixing hole, and the rear flange body is fixed with the bearing inner ring through the bearing rear fixing hole.

2. The noise-reducing multistage differential water pump of claim 1, wherein: the cylinder steel ring is connected with the variable-diameter guide body through a bolt structure, a variable-diameter guide body mounting groove is formed in the inner side of the cylinder steel ring, the variable-diameter guide body comprises a variable-diameter guide body rear cover, a bolt structure mounting groove is formed in the outer side of the variable-diameter guide body rear cover, and the bolt structure is embedded in the bolt structure mounting groove and the variable-diameter guide body mounting groove.

3. The noise-reducing multistage differential water pump of claim 1, wherein: the front end face and the rear end face of the cylinder steel ring are correspondingly provided with flange mounting grooves which are embedded with a front flange body and a rear flange body, the front wall of the front flange body is provided with a front flange hole, the rear wall of the rear flange body is provided with a rear flange hole, the front flange body is fixed with flange mounting groove bolts on a front side rotor through the front flange hole, and the rear flange body is fixed with flange mounting groove bolts on a rear side rotor through the rear flange hole.

4. The noise-reducing multistage differential water pump of claim 1, wherein: annular grooves which are embedded with ball bearings are formed in the front end face and the rear end face of the cylinder steel ring.